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Sender: Paolo Bonzini <paolo.bonzini@gmail.com>
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Date:   Tue, 14 Jun 2022 14:16:00 +0200
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Subject: Re: [PATCH] KVM: nVMX: Don't expose TSC scaling to L1 when on Hyper-V
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To:     Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Cc:     Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
        Ilias Stamatis <ilstam@amazon.com>,
        Maxim Levitsky <mlevitsk@redhat.com>, mail@anirudhrb.com,
        kumarpraveen@linux.microsoft.com, wei.liu@kernel.org,
        robert.bradford@intel.com, liuwe@microsoft.com,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org
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From:   Paolo Bonzini <pbonzini@redhat.com>
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On 6/14/22 06:55, Anirudh Rayabharam wrote:
>> That said, I think a better implementation of this patch is to just add
>> a version of evmcs_sanitize_exec_ctrls that takes a struct
>> nested_vmx_msrs *, and call it at the end of nested_vmx_setup_ctl_msrs like
>>
>> 	evmcs_sanitize_nested_vmx_vsrs(msrs);
> Sanitize at the end might not work because I see some cases in
> nested_vmx_setup_ctls_msrs() where we want to expose some things to L1
> even though the hardware doesn't support it.
> 

Yes, but these will never include eVMCS-unsupported features.

Paolo